Question: Khan.scratchpad.disable(); Tiffany sells magazine subscriptions and earns $$6$ for every new subscriber she signs up. Tiffany also earns a $$28$ weekly bonus regardless of how many magazine subscriptions she sells. If Tiffany wants to earn at least $$36$ this week, what is the minimum number of subscriptions she needs to sell?
Solution: To solve this, let's set up an expression to show how much money Tiffany will make. Amount earned this week $=$ $ $ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus Since Tiffany wants to make at least $$36$ this week, we can turn this into an inequality. Amount earned this week $\geq $36$ Subscriptions sold $\times$ Price per subscription $+$ Weekly bonus $\geq $36$ We are solving for the number of subscriptions sold, so let subscriptions sold be represented by the variable $x$ We can now plug in: $x \cdot $6 + $28 \geq $36$ $ x \cdot $6 \geq $36 - $28 $ $ x \cdot $6 \geq $8 $ $x \geq \dfrac{8}{6} \approx 1.33$ Since Tiffany cannot sell parts of subscriptions, we round $1.33$ up to $2$ Tiffany must sell at least 2 subscriptions this week.